1. Field of the Invention
This invention pertains to masks, and more particularly to apparatus for controlling air movement around a person's lace.
2. Description of the Prior Art
It is well known for persons who ride in open vehicles to wear protective helmets. For example, motorcyclists, snowmobilers, and ice boaters normally include helmets as part of their riding equipment. Although helmets are available in many different designs, almost all of them include a transparent shield that covers most or all of the face. Without question, the helmets contribute to the safety of the persons wearing them.
However, under certain circumstances helmets develop a problem that is annoying and even dangerous. That problem concerns the fogging of the face shield. Whenever the outdoor temperature falls below the dew point of the moisture in a person's breath, that moisture condenses on the inside of the face shield. An even bigger problem concerns the fogging of a person's glasses. It is dangerous, of course, to operate a vehicle with a fogged face shield or glasses.
In an attempt to overcome the face shield and glasses fogging problems, which are most acute in the winter months, it is known to design helmets and face shields with ventilation grooves. U.S. Pat. No. 4,354,285 shows such a helmet and face shield. Another solution is to include a breathing mask with a helmet. The breathing mask may be a separate component that is removably attachable to the helmet. U.S. Pat. Nos. 4,555,815 and 5,003,632 and British patent 1,576,647 describe such combination helmets and masks.
Despite the variety of helmets and masks that are presently available, none is completely satisfactory. Some are undesirably expensive, and others are quite cumbersome to use. Consequently, many persons ride in the winter months with their helmet face shields open, thus defeating their purpose by exposing the person to frost bite and watering eyes.
Therefore, a need exists for improvements in controlling air movement inside protective helmets.